Formation of extracellular neutral proteinase and the stringent response inBacillus subtilis

Riedel, K.; Liebs, P.; Graba, J. P.; Hecker, Michael; Schrapel, D.

doi:10.1007/bf02883234

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…The identification of genes with pleiotropic effects on these and other processes provides a genetic link on which nutritional signals may act (Piggot and Coote 1976;Martin et al 1988). A candidate for such a signal could be the stringent response, a regulatory mechanism that has been implicated in secondary metabolism initiation (Ochi and Ohsawa 1984;Ochi 1986Ochi , 1987a and extracellular enzyme formation (Wambutt et al 1984;Riedel et al 1987). We have recently isolated partially relaxed thiostrepton-resistant mutants of S. clavuligerus which produce reduced amounts of protease and antibiotic in rich media or after nutritional shift-down, a result that would fit this hypothesis (Bascar~n et al, unpublished results).…”

Section: Discussionsupporting

confidence: 53%

Regulation of extracellular protease production in Streptomyces clavuligerus

Bascarán

Hardisson

Braña

1990

Appl Microbiol Biotechnol

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The production of extracellular protease by Streptomyces clavuligerus was strongly influenced by the nature of the nitrogen source. Production took place in batch cultures during growth at low or intermediate growth rates, but was delayed to the post-exponential phase in media supporting high growth rates, Protease formation could be initiated by a nutritional shift-down induced by casamino acids deprivation. Under both types of conditions maximal production was related to the growth rates of the cultures and was stimulated by low concentrations of casamino acids or yeast extract. Some purine compounds also influenced production in shift-down .conditions. A m m o n i u m interfered with protease formation whenever it was added to the medium. Some mutants with altered nitrogen control of primary metabolism were also affected in the production of protease. A partial characterization of the activity indicated that it was due to a single metalloprotease with an apparent molecular mass of 41,700 Da.

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Section: Discussionsupporting

confidence: 53%

Regulation of extracellular protease production in Streptomyces clavuligerus

Bascarán

Hardisson

Braña

1990

Appl Microbiol Biotechnol

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“…leucine) starvation. It has been used previously to study the stringent response in B. subtilis (Belitskiĭ and Shakulov, 1980;Riedel et al, 1987;Eymann et al, 2002). After serine hydroxamate or norvaline were dissolved, the residual medium of M. pneumoniae strains was discarded and replaced by the same medium containing one of the chemical compounds.…”

Section: Transcriptional Response Towards Amino Acid Starvationmentioning

confidence: 99%

Transcription in Mycoplasma pneumoniae

Eilers¹

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Bacteria have developed a broad variety of mechanisms to react to changes in their environment. All mechanisms have in common that an external stimulus is sensed and transduced into a cellular response, either adjustments of enzymatic or physiological activity or alteration of gene expression, aiming to adapt to these new conditions. The stimuli sensed, as well as the output responses, can both be specific or general. As an example, the zinc uptake repressor Zur in the soil bacterium Bacillus subtilis specifically senses intracellular Zn 2+ concentrations and mediates specific responses towards zinc starvation, whereas the expression and activity of general stress-response sigma factor SigS in Escherichia coli is triggered by various signals (Gaballa and Helmann, 1998;Hengge-Aronis, 2002). Cellular recognize and bind to specific promoter sequences (Gruber and Gross, 2003). Often sigma factors themselves are targets of regulatory events, either on the level of expression like B. subtilis SigD (Mirel et al., 2000), or by inactivation through interactions with so called anti-sigma factors. Such anti-sigma factors can either be proteins like FlgM in the case of B. subtilis SigD, or other molecules like 6S RNA in E. coli (Fredrick and Helmann, 1996;Trotochaud and Wassarman, 2004). Besides sigma and anti-sigma factors, other proteins or molecules can also trigger the affinity of RNA polymerase towards specific promoters. al., 2007). Based on their bi-functional role as enzymes and transcription regulators, these proteins are referred to as ´trigger enzymes´.RNA switches are cis-acting regulatory RNA elements that control transcription or translation by anti-termination. They are located in the 5´leader sequence of transcripts and form a terminator structure in the absence of their effector, leading to transcription breakup. If the Post-transcriptional regulation in bacteriaFor a long period, post-transcriptional regulations where thought to occur only by RNA processing or degradation. However, during the last years, another widely distributed mechanism of post-transcriptional control has been discovered involving small, non-coding RNAs (sRNA). These sRNAs can be grouped in two categories, according to their mechanism of regulation: (I) small, trans-acting antisense sRNAs that bind to their target mRNA by base pairing and (II) sRNAs that interact with proteins, thereby triggering their activity. An example of group (II) is E. coli 6S RNA, described previously. sRNAs of group (I) can either effect translation initiation by masking or exposing the Shine-Dalgarno sequence of its target mRNAs (e.g. B. subtilis SR1) or by altering the stability of their targets as for Staphylococcus aureus RNAIII (Heidrich et al., 2006;Huntzinger et al., 2005). Moreover, recent publications showed that also small mRNAs could function as regulatory RNAs, and that titration effects trigger regulatory effects of sRNA with multiple targets (

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